Apparatus for assembling tubes into a finned heat exchanger



Dec. 30, 1958 F. KATZMAN ,8 6,2 0

APPARATUS FOR ASSEMBLING TUBES INTO A FINNED HEAT EXCHANGER Filed Aug. 18, 1954 5 Sheets-Sheet l Fig.l

IN VEN TOR. FREDERICK KATZMAN BY WWW ATTORNEY F. KATZMAN Dec. 30, 1958 APPARATUS FOR ASSEMBLING TUBES INTO A FINNED HEAT EXCHANGER Filed Aug. 18, 1954 5 Sheets-Sheet 3 INVENTOR. FREDERICK KATZMAN ATTORNEY 5 Sheets-Sheet 4 JNVENTOR.

FREDERICK KATZMAN BY b W ATTORNEY I Dec. 30, 1958 F. KATZMAN APPARATUS FOR ASSEMBLING TUBES mm A FINNED HEAT EXCHANGER Filed Aug. 18, 1954 F. KATZMAN Dec. 30, 1958 APPARATUS FOR ASSEMBLING TUBES INTO A FINNED HEAT EXCHANGER 5 Sheets-Sheet 5 Filed Aug. 18, 1954 JNVENTOR. FREDERICK KATZMAN BY 3 g ATTORNEY APPARATUS non AssEMBLtNG TUBES INTO A FINNED HEAT EXCHANGER Frederick Katzman, Louisville, Ky., assignor to Reynolds Metals Company, Louisville, Ky., a corporation of Delaware Application August 18, 1954, Serial No. 450,727 6 Claims. c1. 29-202 The present invention relates to an apparatus for assembling a coil of tubing or thelike into a bank of fins.

In the application of Jesse B. Thomas and Edwin H. Wolff, Serial No. 414,463 filed March 5, 1954 for Method of Making Serpentine Tube Pinned Heat Exchanger and product, there is disclosed a method of making a heat exchanger in which a sinuous coil of tubing is first formed, the return bends at one end then are collapsed, and the coil then is inserted into a bank of slotted fins. The coil then is internally expanded to restore the collapsed ends and to grip thefins.

In this operation, the openings through the fins conform closely to the cross section of the coil, so that considerable frictional resistance is developed in forcing the coil into the bank of fins. The fins are of light gauge metal so they are easily deformed, and as the coil also is formed from thin Wall tubing the force applied to push the coils into the fins must be so distributed that there is no danger of deforming the coils or fins. Also, it is desirable to carry out the assembly and expanding operation rapidly so as to reduce the cost of these operations.

It is an object of the present invention to provide an apparatus for facilitating the assembling of a preformed sinuous coil of tubing or the like into a bank of transverse fins.

A further object is the provision of such an apparatus which is readily adapted to operate with different sizes or shapes of coils.

A further object is the provision of such an apparatus in which the assembling operation is easily carried out without damage to the coil or fins.

Another object is the provision of an apparatus for assembling the coils into the fins and for applying internal pressure for expanding the coil without removing the assembled coil from the assembling apparatus.

These and other objects will be apparent upon consideration of the following specification taken in connection with the accompanying drawing illustrating a preferred embodiment of the invention by way of example and wherein:

Figure 1 shows a side elevation of an embodiment of the invention;

Figures 2A and 28 together show a plan view of Figure 1 on an enlarged scale; Figure ZA showing the left half and Figure 2B the right half;

Figure 3 is an end view on an enlarged scale of Figure 1 as seen from the right;

Figure 4 is an elevation of a detail as viewed from the right indicated by arrow iV, Figure 2A;

Figure 5 is an enlarged side elevation of a detail shown on an enlarged scale;

Figure 6 is a section taken on line VlVl of Figure 2B;

Figure 7 is an enlarged side elevation of the carriage;

Figure 8 is a section taken on line VIil-Vlll of Figure 2B; and

journals for the rollers 21, 21'.

Figure 9 is an elevation view of a bank of fins on a mandrel. v

Referring to the drawing, Figure 1, the base 1 is of welded construction made up of suitable structural steel parts, such as angle bars, channels and the like, which are not described in detail, and at certain positions the base carries foot plates 1a. At its top the base carries inverted channel members 2, 2' (Figs. 1, 2A and 23) having flat steel bars 3, 3' welded to the top surfaces. A cross channel 4 at the right or rear end of the base, and a'similar intermediate cross channel 5 (Fig. 23) support a pair of tracks 6, 6' (Figs. 28 and 3) extending from the right and terminating adjacent the middle of the base on cross channel 5, these tracks being removably positioned on spacer bars 7 (Fig. 3) welded to the base.

At the front or left end of the base a shaft 9 (Figs. 1 and 2A) is rotatably journalled in suitlble bearings Ill and carries a spur gear it near its middle which eshes with the gear teeth on the underside of a rack bar 12 that extends substantiallythe length of the base. The rack bar 12 is mounted in suitable guides 13 located at spaced intervals along the base to guide the rack for longitudinal movement. A capstan 14 is secured to an end of shaft 9 and it will be apparent that by manually rotating the capstan to rotate shaft 9 and gear ll, the rack bar 12 is moved longitudinally because of its engagernent with gear 11.

A pusher carrier indicated generally at 15 (Figsjl, 2B and 3) is secured to the right end of the rack bar 12. This carriage includes a base plate 16 having a groove on its underside to receive the rack bar 12, the base plate being suitably bolted to the rack bar. At its sides the base plate carries bosses 17 in suitable recesses 18 and the stub shafts l9, 19 carried by these bosses provide These rollers bear on tracks 6, 6 to support the pusher carriage for longitudinal movement with the rack bar, and suitable gibs are pro Vided to hold the pusher carrier on the track. At its forward end plate 16 carries an abutment 22 suitably bolted thereto, and a face plate 23 is bolted to the abutment. In face plate 23 are the vertical arcuate grooves 24-, and arcuate slots 25 are provided in the wings or extensions 23a and 23b of the face plate. An apertured plate 26 is fastened to the face plate, and has horizontal oblong apertures 27 (Fig. 6) registering with the arcuate grooves 24 of the face plate, and vertical oblong apertures 28 registering with the arcuate slots 25 in Wings and 2%. In assembled position the plates 23, 26 provide pockets to receive the return bends, indicated generally at 29 (Figs. 23 and 7), of a coil 3-7 of tubing, the return bends abutting against the arcuate grooves and arcuate slots 25. Coil 30, as shown, has three rows of horizontal return bends Ella, 39b and 3% received in the I pockets 27, and two vertical return bends and Eli e and form or" the coil to be acted on, and the assembly, l

comprising plates 23 and 26, may be replaced by a modilied assembly to accommodate other sizes of coils.

Intermediate the ends of the base are secured the brackets 32, 3.. (Figs. 1 and 213) on the bars 3, 3. These brackets each provide a plurality of ap which receive rods 34a, 34b and Me (Fig. 3), m the lowermost rod 34a is in place, the lowermost. runs of coil Slizz rest thereon. Rods 3 in, and 3 50 are removable, and in placing a coil of tubing in the apparatus the coil is positioned with the return bends in the pockets 2'7, 2? and then rods 340., 34-1; and 34c are inserted in the brackets to hold the runs of tubing Zillb and Sllc properly spaced horizontally. Adjacent the top, the

brackets carry a rotatable shaft 35 having rods or fingers 36 extending radially therefrom in alignment, and by rotating the shaft 35 to direct the rods 36 downwardly, they pass between the coils of the tubing to hold the coils in proper vertical alignment. Knobs 37 may be provided on shaft 35 to facilitate manual rotation of the shaft.

A base plate 39 (Figs. l and 2A) is removably secured to the bars 3, 3, and at its forward end the plate carries an abutment 41 straddling the notch 42 in the forward end of the base plate. The abutment plate has the vertical slots 43 (Fig. 4) in its rear face, separated by ribs, to receive the return bends at one end of the coil, the ribs at its sides being indicated by the numerals 44, 44'. Rearwardly of this abutment, rails 45, 45' are secured to the base plate, and they extend forwardly beyond the notch 42. The upper surfaces of these rails are elevated above plate 39. At the rear ends of the rails are side guides or stops 46, 46' (Fig. 23) also carried by the base plate adjacent notch 47. The rear ends of rails 45, 45 extend beyond recess 47. Guides 46, 46 preferably are notched to accommodate and position the end plates of the bank of fins.

t will be noticed that the base plate 39 carrying the abutment 41, rails 45, 45' and guides or side stops 46, 46 is removable as a unit, and for operating on other tube and fin arrangements, this unit can be replaced by another suitable unit having the proper arrangement of abutment, rails and stops.

The fins into which the tube coil is to be inserted, are strung on a loading rack indicated generally by numeral 48 (Figs. 2A and 9) which comprises two mandrel rods 49, 49' passing through and attached to a stop bar 50 into a cross bar 51, and pairs of short gauge rods 52 and 52' extend from the stop bar. The rods 49, 49 are approximately the diameter of the tubes, and the bank of fins 53 having end plates 54, 54' are strung on these rods while the mandrel is in a vertical position, as shown in Fig. 9, with the guide rods 52, 52' engaging the end plate 54. The guide rods 52, 52' are out of alignment with the holes through end plate 54, and thus serve as a gauge to space the end plate 54 from bar 50. The rods 49, 49' are approximately the length of the bank of fins, and extend slightly beyond the end plate 54.

The abutment plate 41 (Figs. 2A and 4) has slots 55, 55 in its upper edge, so that when inserting a fin bank the rods 49, 49 and 52, 52' can be inserted into these slots with the lower edges of the fins resting on the rails 45, 45. The space between the forward end of the rails 45, 45' and abutment 41 allow the end plate 54 to pass therebetween into notch 42 in plate 41, and the side ribs 44, 44 of the abutment engage the insides of the flanges of the end plate. The end plate 54' passes through the space between the rails and side guides 46, 46' (Fig. 2B), with the flanges of the end plate engaging the side guides 46, 46. The end plates thu hold the bank of fins between them firmly in place. When a coil of tubing is positioned on the pusher carriage, guide bars 34a, 34b, 34c and fingers 36 hold the tubes in proper alignment with the openings through the bank of fins. Now, when the pusher carriage 15 is brought forward, the tube ends enter the openings in the end plate and fins, and as the tubes advance into the bank of fins, the mandrel rods 49, 49' move out ahead of them, as will now be described.

Forward of the abutment plate 41 (Figs. 2A and a carriage plate 56 is secured to the rack bar 12, this carriage plate having upstanding side bosses 57, 57. On each side boss a finger or pawl 53 is pivoted on a pivot screw 59 and is held by a spring 61 against a top pin 62. This pawl has a bevelled rear edge 63. The carriage plate is held on the rack 12 by screws 64 passing through elongated slots 65 to permit the carriage to be adjusted in the rack. When the rack 12 and pusher carriage 15 are moved forwardly, the pawls 58 engage 4 bar 51 and thus move the bar and mandrel rods 49, 49'

forwardly out of the fins at the same rate the tubes advance into the fins. The rods 34a, 34b and 340 are manually removed after the ends of the coil enter the fin bank. When the pusher carriage reaches the fingers 36, these fingers, together with shaft 35, are rotated out of the way by engagement with the upper edge of apertured plate 26, of the pusher carriage. It will be understood that fingers 36 are of such length, and shaft 35 is so located, that there is room for the fingers and shaft to rotate the required amount. The movement of the pusher carriage ends when the carriage 15 abuts the rear edge 67 (Figs. 1 and 2B) of base plate 39.

A plurality of tracks 68 (Fig. 2A) are mounted on a cross bar 69 at the front of the machine, these tracks being at an elevation so that, as the mandrel assembly 48 moves forwardly, the tracks engage under bars 51, 50 to prevent the mandrel assembly falling or tilting. When the movement of rack bar 12 and plate 56 is reversed toward the right, the inclined pawl face 63 rides under bar 50, so that the mandrel assembly remains on the tracks 68.

A suitable apparatus 71 for developing pressure is positioned within the frame, and has flexible pressure tubes 72, 73 connected therewith terminating in suitable quickly detachable couplings 74 and 75 which are adapted to be connected to ends 30 30g of the tube. The pressure developing apparatus may comprise a pump 76, operated by an air motor M, which in turn is operated from an air line 77 by means of a suitable automatically controlled four way valve in known manner. Water from a suitable supply at ordinary pressure flows through the piston pump and through line 72 to the coil 30 in the machine, and the out line 73 past a manually operated valve 78. When the condenser coil is filled with water, valve 78 is closed, and the pump is started to develop the desired pressure in the coil to expand the coil. After expansion is complete, valve 78 is opened, and valve 79 in the air line is opened so the air admitted into line 72 blows out the water from the condenser, couplings 74, 75 then are removed, and the coil assembly then is removed from the apparatus.

The operation of the apparatus now will be described. A bank of fins 53 mounted on a mandrel as shown in Fig. 9, is placed on the rails 45, 45 with the rods 49, 49', 52 and 52' extending through the slots 55, 55 in abutment plate. The forward end plate 54 of the fin a sembly engages the abutment plate 41 with its flanges embracing end ribs 44, 44' and the rear end plate 54 is received between guides 46, 46. The mandrel rods 49, 49 extend through the bank of fins. A coil now is placed with its ends received in the sockets 27, 28 of the carriage 15, and a rod 34 is inserted through brackets 32, 32 to support the bottom row of tubes 30a. The rods 34b and 340 then are inserted through brackets 32, 32' to support the rows 30b and 30c of tubes. Shaft 35 then is turned by knobs 37 to locate the fingers 36 between the coils, this being accomplished easily because of the guiding action of the return bends. It will be observed that the collapsed return bends are located at the left end of the coil.

The capstan 14 now is rotated counter clockwise to advance the carriage 15 to push the coil into the openings in the bank of fins, and at the same time, by means of pawl 58 on plate 56, to withdraw the mandrel bars from the fins. As soon as the coils enter the fins, the rods 34a, 34b and 340 are manually withdrawn, and the operation of the capstan is resumed until the coil is inserted into the fins. It is not necessary to manually turn shaft 35 to remove fingers 36, because when the carriage 15 engages the fingers they are rotated clockwise out of the way. A suitable lubricant may be employed to facilitate passage of the coils into the fins.

The capstan 14 now is turned clockwise to retract the carriage 15, and pawl 58 rides under bar 50 leaving the mandrel assembly resting on tracks 68. The mandrel assembly is now removed and the apparatus is ready to receive another fin assembly and coil.

If desired, the coil may be expanded before it is removed from the apparatus, by connecting the couplings 74, 75 to the ends 301, 30g, and filling the coil With Water, and then applying pressure to the water in the coil. After expansion is completed the water is blown out by compressed air, the couplings are removed, and the condenser then is lifted from the apparatus.

It will be appreciated that I have provided a simple and effective apparatus for assembling a bank of fins having a series of openings onto a sinuous coil of tubing presenting a corresponding series of hairpin tubes interconnected at the rear end of the coil, each hairpin tube projecting forwardly therefrom and terminating at its front end in a return bend. This apparatus comprises: means for supporting a bank of fins with the corresponding openings of successive fins in alignment with each other; means for holding said coil with its front end spaced rearwardly from the rear end of the bank and for aligning each hairpin tube with its corresponding opening in the bank; and means for moving the bank and coil relatively toward each other until the front end of each hairpin tube enters the corresponding fin opening and for continuing the movement until the front ends of the hairpin tubes project through the front end of the bank. Preferably the holding means includes an abutment against which the front end of the bank rests and the moving means includes a manually actuated pusher for moving the tubes into and through the openings.

Once assembled, the ,tubes may be expanded after removal from the apparatus. Preferably they are expanded before such removal; hence the apparatus also includes an hydraulic pressure means adapted for connection to an end of said coil and operative, when connected and actuated, to expand the straight runs of each hairpin tube into firm contact with the fins of the bank. Where the front end of each hairpin tube is flattened to facilitate assembly, the expansion of the straight runs will be accompanied by a restoration of the flattened front end bends substantially to their original shape.

I claim as my invention:

1. An apparatus for threading a sinuous coil endwise into a bank of apertured cross fins and end plates comprising: a base; means on said base forming a lower supporting plane for a bank of fins; an abutment plate on said base at one end of said means arranged with its rear face normal to and above said means and having pockets in its rear face located to align with the coil ends; a guide mandrel assembly removably mounted on said abutment plate above said first means and having guide mandrel rods extending through said apertured cross fins and end plates; means on said base adapted to support said sinuous coil in alignment with said apertured fins and end plates; means on said base movable forward to force said coil ends forward into said fins and end plates; and means connecting said last means and guide mandrel assembly to pull said guide mandrel rods from said aper tured fins and end plates simultaneously as said coil is moved forwardly.

2. An apparatus as specified in claim 1 wherein: said abutment plate has slots in its upper edge to receive the guide mandrel rods of said guide mandrel assembly, said guide mandrel assembly being removable from said slots by a lifting movement.

3. An apparatus as specified in claim 1 wherein: said means for connecting said last means and said guide mandrel assembly includes means automatically disengaging said guide mandrel assembly when said last means is moved in a rearward direction.

4. An apparatus as specified in claim 1 wherein: said abutment plate includes side flanges for laterally indexing the end plate at the forward end of the bank of fins.

.5. The apparatus of claim 1 wherein: said abutment plate is spaced from the forward end of said means forming a lower supporting plane for the bank of fins to accommodate the end plate at the forward end of said bank.

6. An apparatus as specified in claim 3 having: a support on said base for receiving and guiding said guide mandrel assembly as it is pulled from said fins and end plates.

References Cited in the file of this patent UNITED STATES PATENTS 1,020,150 McKeon Mar. 12, 1912 1,802,929 Seelert Apr. 28, 1931 1,835,111 Dow Dec. 8, 1931 2,057,244 Maynes Oct. 13, 1936 2,154,855 Lear Apr. 18, 1939 2,181,108 Przyborowski Nov. 21, 1939 2,224,549 OBrien Dec. 10, 1940 2,688,178 Boyd Sept. 7, 1954 2,747,258 Kramer May 29, 1956 FOREIGN PATENTS 687,817 Great Britain Feb. 18, 1953 

